The present invention relates to an apparatus for cleaning wells and, more specifically, relates to apparatus which is used to remove rust and mineral deposits residing in the perforations of a water well casing.
The ability to obtain large quantities of water is a vital necessity of agriculture, both farming and ranching. It has long been the practice to dig or drill water wells into the earth and to pump the water out of the well. Typically a casing, which has perforations in the bottom area, is placed into the drilled well and after gravel packing the production area of the perforated casing the well is put into production by placing a pump at the bottom of the well. Such wells are vital in the Great Plains area of this country and it is not unusual for a well having a sixteen inch casing to produce from 400 to 1800 gallons per minute, although a well producing 1000 gallons per minute is generally considered a good well.
The static water level in the northern Panhandle area is approximately 400 feet from the surface or ground level. When the casing perforations become clogged the water level inside the casing will drop to a static level of approximately 550 feet or whatever level the pump is set at. If the well does not make enough water, the pump will start to pump air. Often it can ruin a pump and waste gas. When the pump starts sucking air, it is called surging or pumping off. When the water level drops the only alternative to obtain water is to drill another well. At current prices, by using the inventive device, the well can be cleaned out for about 20% of the cost of drilling a new well. After cleaning, the amount of water flow will increase and the amount of gas used will decrease by about one-third (1/3), due to the fact that the water level will rise by approximately 150 feet in the well casing. This energy reduction will save the farmer substantial costs, and ease the current energy crisis.
The type of casing employed in these wells is perforated typically by means of a cutting torch, and the perforations comprise eight to twelve-inch long vertical slots spaced approximately four inches apart on the circumference of the casing. Forming the perforations in this manner usually results in the formation of burrs along the perforations on the inside of the casing. The perforations in the casing are then repeated at vertical intervals approximately equal to the length of the perforation, i.e., eight to twelve-inches above and below a ring of perforations will be another ring of perforations.
At the beginning of production of a well, the perforations perform entirely as desired; however, as the well becomes older and the well is in production for a while, the perforations tend to become plugged and clogged with mineral particles in the water and with rust formed at the edges of the perforations of the pipe. Principally, the plugging of the casing perforations in a water well is directly related to rust. There have been many previous attempts at efficiently cleaning the perforations of this rust. One approach is to employ a rotating wire brush or the like, which is run down inside the casing and then rotated relative to the casing. The bristles of the brush are intended to knock loose the rust particles. Another approach has been to utilize streams of extremely high-pressure water in the casing; for example, water pressures up to 12,000 psi have been employed. However, in the vast majority of cases, all of these efforts to clean the casing perforations to improve the water production, have been unsuccessful or inefficient.